Tested - 16.8mH inductor replacement with Erse 17mH inductor on 1.2's
OldmanSRS
Posts: 419
I replaced the stock SDA 16.8 mH inductor (2.7 Ohms DCR) with the Erse SuperQ 17 mH inductor (.4 Ohms DCR). The overall speaker DCR decreased from 4.3 Ohms to 3.1 Ohms.
The results were very positive:
At first I thought bass response decreased but more listening on many different recordings and test tones revealed the low bass was still all there but the lower mid-bass decreased. The best description is the bass tightened up, became more dynamic-accurate and less lazy, muddy or boxy. A solo standup bass has 95% of the impact as before but is MUCH more defined and tight. You can hear the fingers on the strings and the movement of the hand on the kneck. Previously these were obscured by some slight muddiness and overhang. The tired cliche about air around the instrument does indeed apply to the bass now.
The soundstage narrowed a little but deepend by the same amount. Hints of out-of-phase hoaky effects dropped dramatically. There are still behind-you surprises but now they are more anchored and less phantom-like.
The midrange jumps out now. My impression of the 1.2's has always been "layed back" and a little heavy in the 700 - 200 Hz range. Bells, chimes higher organ notes, accoustic guiter strings, and other lower midrange sounds now pop with surprise.
The center is more defined and anchored. Upper midrange and into the lower trebble is more impressive and natural. I think this is due to the better damping and lower overhang from the better controlled SDA MW's
On very wide recordings there is no hole-in-the middle. The soundstage is more evenly distibuted across the front. Before the mod, if I walked toward the speakers, while a solo vocal was playing the center soundstage began to fade until at the plane of the speakers, it was as if you were standing in a void. Now the vocals are clear and only at the speaker plane do they sound reduced but never absent as before.
Ok now for the bad. The SL2000's seem a little bright to me now. They are acceptable but with the improved midrange and tighter bass, they stand out and are a little annoying.
Damn.
For $68 this a one heck of a good mod. I was prepared to be dissapointed but alas, I will not be sending the inductors back for a refund.
The results were very positive:
At first I thought bass response decreased but more listening on many different recordings and test tones revealed the low bass was still all there but the lower mid-bass decreased. The best description is the bass tightened up, became more dynamic-accurate and less lazy, muddy or boxy. A solo standup bass has 95% of the impact as before but is MUCH more defined and tight. You can hear the fingers on the strings and the movement of the hand on the kneck. Previously these were obscured by some slight muddiness and overhang. The tired cliche about air around the instrument does indeed apply to the bass now.
The soundstage narrowed a little but deepend by the same amount. Hints of out-of-phase hoaky effects dropped dramatically. There are still behind-you surprises but now they are more anchored and less phantom-like.
The midrange jumps out now. My impression of the 1.2's has always been "layed back" and a little heavy in the 700 - 200 Hz range. Bells, chimes higher organ notes, accoustic guiter strings, and other lower midrange sounds now pop with surprise.
The center is more defined and anchored. Upper midrange and into the lower trebble is more impressive and natural. I think this is due to the better damping and lower overhang from the better controlled SDA MW's
On very wide recordings there is no hole-in-the middle. The soundstage is more evenly distibuted across the front. Before the mod, if I walked toward the speakers, while a solo vocal was playing the center soundstage began to fade until at the plane of the speakers, it was as if you were standing in a void. Now the vocals are clear and only at the speaker plane do they sound reduced but never absent as before.
Ok now for the bad. The SL2000's seem a little bright to me now. They are acceptable but with the improved midrange and tighter bass, they stand out and are a little annoying.
Damn.
For $68 this a one heck of a good mod. I was prepared to be dissapointed but alas, I will not be sending the inductors back for a refund.
'65 427 Shelby Cobra
'72 Triumph TR-6
__________________
'88 Polk SDA SRS 1.2, with upgraded XO caps and Erse SDA inductors
'86 Polk SDA CRS+
'84 Polk Monitor 10A (Peerless tweeters)
'05 HSU VTF-3 Sub (Original OEM)
'20 HSU VTF-3 Sub (three more, 100% cloned)
'93 Carver TFM-35
'88 Carver M-1.0t
'88 Adcom GFT-555
'88 Adcom GFP-555
'88 Adcom GFA-555 (upgraded/restored)
'88 Adcom GFA-555 (a second one upgraded/restored)
'05 Onkyo DV-555 media
'89 Fosgate 360 Digital Space Matrix
'89 Fosgate 360 Digital Space Matrix, internal surround amp bridged to drive only a center channel
'91 Kenwood Basic M1D Amp
'89 Pioneer Laser Disc media
'89 Sony SuperBeta HiFi media
One PGA2310 based custom built remote volume control
Four Polk T-15's
Four Polk TSi-200's
Four Polk TSi-100's
Two Polk CS-10's
'72 Triumph TR-6
__________________
'88 Polk SDA SRS 1.2, with upgraded XO caps and Erse SDA inductors
'86 Polk SDA CRS+
'84 Polk Monitor 10A (Peerless tweeters)
'05 HSU VTF-3 Sub (Original OEM)
'20 HSU VTF-3 Sub (three more, 100% cloned)
'93 Carver TFM-35
'88 Carver M-1.0t
'88 Adcom GFT-555
'88 Adcom GFP-555
'88 Adcom GFA-555 (upgraded/restored)
'88 Adcom GFA-555 (a second one upgraded/restored)
'05 Onkyo DV-555 media
'89 Fosgate 360 Digital Space Matrix
'89 Fosgate 360 Digital Space Matrix, internal surround amp bridged to drive only a center channel
'91 Kenwood Basic M1D Amp
'89 Pioneer Laser Disc media
'89 Sony SuperBeta HiFi media
One PGA2310 based custom built remote volume control
Four Polk T-15's
Four Polk TSi-200's
Four Polk TSi-100's
Two Polk CS-10's
Post edited by OldmanSRS on
Comments
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Glad to hear the results are postive! Why did you pick the Erse SuperQ 17 inductor? Certain properties/specs, cost?
I plan to do this upgrade to my 2.3TL's.
I've done the crossovers and generally cleaned up/ improved connections a previous modder had buggered up. Though the crossovers are still burning in (160 hours so far) the speakers are starting to open up.
The bass became very recessed just after the xover upgrade. It's slowly returning, but I'm after a little more. I think the lower bass output is probably more due to room placement than it not being there. Unfortuneately, the layout of the room, i.e. the distance from the back wall, prevents optimal positioning.
Right now I have a powered sealed subwoofer going at very low volume, and it seems to flesh out the bottom nicely. From what I've read this shouldn't be necessary - perhaps the inductor replacement will fix that :cool:"Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer -
The results were very positive...
For $68 this a one heck of a good mod. I was prepared to be dissapointed but alas, I will not be sending the inductors back for a refund
Reasonable skepticism is a good thing. Thanks for sharing your results.Ok now for the bad. The SL2000's seem a little bright to me now. They are acceptable but with the improved midrange and tighter bass, they stand out and are a little annoying.
You may find the RD0194 more balanced.Proud and loyal citizen of the Digital Domain and Solid State Country!
